Results: The sepsis mortality in small and medium-sized cities and rural areas declined obviously over time. The mortality of the subpopulations aged 1–54 years tended to be lower than the national averages.In contrast, the sepsis mortality among neonates and the elderly (75 years) was obviously higher than national averages. While the mortality in the elderly declined between 2003 and 2007, the neonate sepsis mortality increased dramatically, especially among male neonates. The overall positivity of blood
culture were 17.0%, 13.3% and 10.6% among neonatal, pediatric and adult patients with suspected sepsis, respectively; this proportion tended to decrease over time. Among identified microorganisms, the proportions of Gram (+) and (–) bacteria were similar (47.2% vs. 44.5%) among adult patients, while Gram (+) bacteria was predominant among neonatal (77.4%) and pediatric (73.2%) patients and increased in prevalence over time. The positivity of blood cultures and proportions of microorganisms varied by geographical region across mainland China. Sepsis with fungus was rare but was more prevalent in adult sepsis patients (6.4%) than in neonatal patients (0.8%).